OpsMgr 2007: Monitor or rule targeted at computer group does not generate alerts

One issue we still seem to see a lot of confusion about is the way that you use System Center Operations Manager 2007 to target computer groups. It's different than the method you might have used in Microsoft Operations Manager 2005 so if you try to do it the old way then you may not get the results you expect. For example, say you target a rule or monitor to a computer group in SCOM 2007 by following these steps:

Create a computer group in the Authoring console Create a monitor/rule and target the computer groupUse eventcreator to create an event that is being monitored and configure it to generate an alert

All seems fine until the event occurs but you don't receive any alerts and the computer appears healthy.

This is actually by design with System Center Operations Manager 2007. The proper way to target a group of computers in SCOM 2007 is to target your rule or monitor at an already existing suitable class of object, leaving the rule or monitor disabled (the default), then create an override for your specific group that enables the rule or monitor only for that group. To give you an example, follow these steps: 1. Create your group and add the members you wish to monitor. 2. Create your rule/monitor and target it at a suitable class. For example if the machines you wish to monitor are all SQL servers, you can use the SQL Computers class. 3. Ensure the rule/monitor is disabled by default. To do this, click the General tab in the Properties dialog box for the rule or for the monitor in question, then make sure that the Rule is Enabled check box is cleared (not checked). 4. Create an override for the rule/monitor targeted at your group and sets the Enabled property to True. To do this follow these steps:

a. In the Authoring pane in the Operations Console, locate the rule or the monitor. b. Right-click the rule or the monitor, point to Overrides, point to Override the Rule or to Override the Monitor, and then click For a group. c. Click the group that you want to use, and then click OK. d. Click to select the Override check box, and then click True under Override Setting.

The Operations Manager Team blog wrote a couple great posts about this a few months back so if you'd like to read more I'd suggest checking them out: